The reliable and effective connection of the grounding wire of power equipment is the fundamental guarantee to ensure the safe operation of maintenance personnel. The grounding wire is the connection between the power equipment and the ground network, and the primary task is to hang the grounding wire for power outage maintenance. Therefore, in the "Twenty-five Key Requirements for Preventing Major Accidents in Power Production", it is clearly stated that the conduction inspection of the down conductor of the grounding device should be carried out once a year. This grounding down conduction tester is a portable tester with a high degree of automation developed by our company, which is used to ensure the good conductivity of the ground wire for power outage maintenance in the substation. The instrument is controlled by a high-performance microcontroller, which can realize the intelligent testing process.